Diigo – social bookmarking

Social bookmarking is a method for Internet users to organize, store, manage and search for bookmarks of resources online. Two of the more popular bookmarking services available are Diigo and Delicious Tagging is a significant feature of both of these social bookmarking systems, enabling users to organize their bookmarks in flexible ways. I have an account on both systems but my favourite by a long shot is Diigo.